Double-cavity series piezoelectric pump based on coanda effect jet element

Abstract

The utility model provides a double-cavity series piezoelectric pump based on a coanda effect jet element, which comprises two pump cavities connected in series, each pump cavity is of a step-shaped structure, and a pump cavity interface is arranged at the step junction; one end of the communicating pipe and the inlet pipe intersect at the pump cavity connector of the inlet pump cavity, and the other end of the communicating pipe and the outlet pipe intersect at the pump cavity connector of the outlet pump cavity. According to the utility model, the flow of the pump and the kinetic energy of the pumped fluid are increased by adopting a double-cavity serial connection structure, so that the back pressure performance of the micropump at the outlet is improved. A coanda effect jet flow element of a three-dimensional structure is designed in the micro-pump, beneficial vortexes are formed in the coanda effect jet flow element, the flow difference of a flow dividing pipe is increased in the discharging process of the micro-pump, the flow of a pump outlet is improved, and then the volume efficiency of the micro-pump is improved. Based on the coanda effect jet element, the net flow and the back pressure performance of the micropump are greatly improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of piezoelectric pumps, and in particular relates to a double-cavity series piezoelectric pump based on a Coanda effect jet element. Background Art

[0002] Piezoelectric pump is a kind of reciprocating membrane electric micro pump, which uses the inverse piezoelectric effect of piezoelectric material to bend and deform, so that it can be used as a vibrating diaphragm to change the volume of the pump chamber, thereby achieving the purpose of conveying fluid. It has the advantages of easy manufacturing, low power consumption, fast response, and no electromagnetic interference, so it is widely used in chemical analysis, biochip and other fields.

[0003] Traditional valveless piezoelectric pumps use the different flow resistances in the forward and reverse directions of the flow tube to achieve unidirectional fluid pumping. The flow rate or efficiency of the pumped fluid is relatively low, the flow rate of the pumped fluid is very slow, and the back pressure performance of the outlet is very poor. For example, a synthetic jet-based four-way piezoelectric micropump for gas delivery made by Dau et al. of Ritsumeikan University in Japan has a planar structure and has disadvantages such as low flow rate. It is difficult to meet the current demand for large-flow piezoelectric pumps. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides a double-cavity series piezoelectric pump based on a Coanda effect jet element, which is used to increase the flow rate of the piezoelectric pump.

[0005] The utility model achieves the above technical objectives through the following technical means.

[0006] A dual-cavity series piezoelectric pump based on a Coanda effect jet element: comprising an inlet pump cavity, an outlet pump cavity, an inlet pipe, an outlet pipe and a connecting pipe; the pump cavity is a stepped structure, and a pump cavity interface is provided at the junction of the steps; one end of the connecting pipe intersects with the inlet pipe at the pump cavity interface of the inlet pump cavity, wherein the inlet pipe is located on the thicker side of the pump cavity and transitions with the pump cavity interface at an acute angle, and the connecting pipe is located on the thinner side of the pump cavity and transitions smoothly with the pump cavity interface; the other end of the connecting pipe intersects with the outlet pipe at the pump cavity interface of the outlet pump cavity, wherein the connecting pipe is located on the thicker side of the pump cavity and transitions with the pump cavity interface at an acute angle, and the outlet pipe is located on the thinner side of the pump cavity and transitions smoothly with the pump cavity interface.

[0007] Furthermore, the inlet pump chamber and the outlet pump chamber are arranged on both sides of the pump body opposite to each other and are staggered front to back.

[0008] Furthermore, the pump body is provided with an inlet and an outlet at the front and rear ends respectively, and the inlet and the outlet are coaxially arranged opposite to each other; the two pump chambers are respectively located on both sides of the axis from the inlet to the outlet.

[0009] Furthermore, one end of the inlet pipe is connected to the inlet, and the other end is connected to the inlet pump chamber after being bent; one end of the outlet pipe is connected to the outlet, and the other end is connected to the outlet pump chamber after being bent.

[0010] Furthermore, the bending angle is 45°.

[0011] Furthermore, the connecting pipe is inclined at 45° relative to the axis from the inlet to the outlet.

[0012] Furthermore, the bottom surface of the pump chamber is covered with a vibration diaphragm, and a piezoelectric vibrator is provided on the vibration diaphragm.

[0013] Furthermore, the two pump chambers have the same structure.

[0014] Furthermore, the bottom surface of the pump chamber is circular.

[0015] Furthermore, half of the pump chamber interface is opened on the surface of a thicker section of the pump chamber, and the other half is connected to a thinner section of the pump chamber through a bell-mouth structure.

[0016] The beneficial effects of the utility model are:

[0017] (1) The utility model provides a dual-chamber series piezoelectric pump based on a Coanda effect jet element, which adopts a dual-chamber series structure to increase the pump flow rate and the kinetic energy of the pumped fluid, thereby improving the back pressure performance of the micropump at the outlet.

[0018] (2) The utility model provides a three-dimensional Coanda effect fluidic element, which forms a beneficial vortex in the Coanda effect fluidic element. During the discharge process of the micropump, the flow difference of the shunt pipe is increased, the pump outlet flow rate is increased, and the volumetric efficiency of the micropump is improved. Based on the above Coanda effect fluidic element, the net flow and back pressure performance of the micropump are greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a cross-sectional view of the piezoelectric pump of the utility model;

[0020] Figure 2 This is a three-dimensional diagram of the internal pump chamber and various connecting pipelines of the piezoelectric pump of the utility model;

[0021] FIG3( a ) is a schematic diagram of the discharge state of the piezoelectric pump of the present invention;

[0022] FIG3( b ) is a schematic diagram of the suction state of the piezoelectric pump of the present invention.

[0023] Reference numerals:

[0024] 1- pump body; 11- inlet pipe; 12- inlet diversion pipe; 13- connecting pipe;

[0025] 14- outlet shunt pipe; 15- outlet pipe; 16- inlet pump chamber; 17- outlet pump chamber;

[0026] 18- pump chamber interface; 2- inlet; 3- outlet; 4- piezoelectric vibrator;

[0027] 5-Vibrating diaphragm. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0029] like Figure 1 and Figure 2 The piezoelectric pump shown has an inlet 2 on the left side of the pump body 1 and an outlet 3 on the right side, and the inlet 2 and the outlet 2 are coaxially arranged opposite to each other. The pump body 1 is provided with two pump chambers, which are respectively located on the upper and lower sides of the pump body 1, and the two pump chambers are staggered along the liquid pumping direction; the side close to the inlet 2 is the inlet pump chamber 16, and the side close to the outlet 3 is the outlet pump chamber 18. The outer bottom surface of the pump chamber is covered with a vibration diaphragm 5, and a piezoelectric vibrator 4 is provided on the vibration diaphragm 5; when in use, the vibration diaphragm 5 is driven to reciprocate by applying an alternating voltage to the piezoelectric vibrator 4, thereby periodically changing the volume of the pump chamber.

[0030] The two pump chambers have the same structure, and the whole is divided into two sections by a stepped structure, wherein the section near the inlet 2 is thicker and the section near the outlet 3 is thinner. A pump chamber interface 18 is provided on the side of the pump chamber away from the vibration diaphragm 5, and the pump chamber interface 18 is located at the step between the two sections of the pump chamber; wherein half of the pump chamber interface 18 is directly opened on the surface of the thicker section of the pump chamber, and the other half is connected to the thinner section of the pump chamber through a bell mouth structure. In the figure, for the convenience of setting the vibration diaphragm 5, the bottom surface of the pump chamber is set to a circular structure.

[0031] Several pipes are provided in the pump body 1 to connect the inlet 2, the outlet 3 and the two pump chambers, including the inlet pipe 11, the outlet pipe 13 and the connecting pipe 13. Among them, one end of the inlet pipe 11 is connected to the inlet 2, and the other end is provided with a 45° bend section, which is called the inlet diverter pipe 12 for convenience of expression. Similarly, one end of the outlet pipe 15 is connected to the outlet 3, and the other end is provided with a 45° bend section, which is called the outlet diverter pipe 14. The main parts of the inlet pipe 11 and the outlet pipe 15 are arranged along the axis from the inlet 2 to the outlet 3, the inlet diverter pipe 12 is parallel to the outlet diverter pipe 14, and the two are connected through the connecting pipe 13. The connecting pipe 13 is inclined at 45° relative to the axis from the inlet 2 to the outlet 3, one end of the connecting pipe 13 and the inlet diverter pipe 12 intersect at the pump chamber interface 18 of the inlet pump chamber 16, and the other end of the connecting pipe 13 and the outlet diverter pipe 14 intersect at the pump chamber interface 18 of the outlet pump chamber 17. At the pump chamber interface 18 of the inlet pump chamber 16, the connecting pipe 13 is located at the bell mouth side; at the pump chamber interface 18 of the outlet pump chamber 17, the outlet diverter pipe 14 is located at the bell mouth side.

[0032] As shown in FIG. 3( a ) and FIG. 3( b ), during operation, alternating voltage signals with the same frequency and opposite directions are applied to the piezoelectric vibrators 4 of the two pump chambers, so that the two pump chambers work asynchronously, that is, when one pump chamber expands, the other pump chamber contracts.

[0033] As shown in Figure 3(a), the inlet pump chamber 16 expands, and liquid is sucked in by the inlet pipe 11 and the connecting pipe 13 respectively; however, since there is an acute angle transition between the inlet shunt pipe 12 and the pump chamber interface 18, and a smooth transition between the connecting pipe 13 and the pump chamber interface 18, the resulting Candal effect causes a pressure difference due to the different pressures on both sides when the fluid flows through, resulting in a deflection of the jet at the pump chamber interface 18, and the liquid sucked in from the inlet pipe 11 is much larger than the connecting pipe 13. At the same time, the outlet pump chamber 17 contracts to discharge the liquid, and here there is an acute angle transition between the connecting pipe 13 and the pump chamber interface 18, and a smooth transition between the outlet shunt pipe 14 and the pump chamber interface 18. Also due to the Candal effect, the liquid is mainly discharged from the outlet pipe 15 to the outlet 3, and only a small amount of liquid flows from the connecting pipe 13 into the inlet pump chamber 16. At this time, the piezoelectric pump is relatively in a discharge state.

[0034] Similarly, as shown in FIG3(b), the inlet pump chamber 16 contracts to discharge liquid, and the outlet pump chamber 17 expands to inhale liquid. Based on the Candal effect, a large amount of liquid on the inlet pump chamber 16 side flows into the connecting pipe 13 along with a small amount of liquid on the inlet pipe 11 side at the pump chamber interface 18 of the inlet pump chamber 16; and at the pump chamber interface 18 of the outlet pump chamber 17, based on the Candal effect, the liquid in the connecting pipe 13 mainly flows into the outlet pump chamber 17, while a small amount is discharged outward through the outlet pipe 15. At this time, the piezoelectric pump is relatively in the suction state.

[0035] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] The present invention is not limited to the above-mentioned embodiments. Without departing from the essential content of the present invention, any obvious improvement, replacement or deformation that can be made by those skilled in the art shall fall within the protection scope of the present invention.

Claims

1. A dual-chamber series piezoelectric pump based on a Coanda effect fluidic element, characterized in that: The invention comprises an inlet pump chamber (16), an outlet pump chamber (17), an inlet pipe (11), an outlet pipe (15) and a connecting pipe (13); the pump chamber is a stepped structure, and a pump chamber interface (18) is provided at the junction of the steps; one end of the connecting pipe (13) and the inlet pipe (11) meet at the pump chamber interface (18) of the inlet pump chamber (16), wherein the inlet pipe (11) is located on the thicker side of the pump chamber and makes a sharp transition to the pump chamber interface (18), and the connecting pipe (13) is located on the thinner side of the pump chamber and makes a smooth transition to the pump chamber interface (18); the other end of the connecting pipe and the outlet pipe (15) meet at the pump chamber interface (18) of the outlet pump chamber (17), wherein the connecting pipe (13) is located on the thicker side of the pump chamber and makes a sharp transition to the pump chamber interface (18), and the outlet pipe (15) is located on the thinner side of the pump chamber and makes a smooth transition to the pump chamber interface (18).

2. The dual-chamber series piezoelectric pump based on the Coanda effect fluidic element according to claim 1, characterized in that: The inlet pump chamber (16) and the outlet pump chamber (17) are arranged on two sides of the pump body (1) opposite to each other and are arranged in a front-to-back staggered manner.

3. The double-chamber series piezoelectric pump based on the Coanda effect jet element according to claim 2 is characterized in that: The pump body (1) is provided with an inlet (2) and an outlet (3) at the front and rear ends respectively, and the inlet (2) and the outlet (3) are coaxially arranged opposite to each other; the two pump chambers are respectively located on both sides of the axis from the inlet (2) to the outlet (3).

4. The double-chamber series piezoelectric pump based on the Coanda effect fluidic element according to claim 3 is characterized in that: One end of the inlet pipe (11) is connected to the inlet (2), and the other end is connected to the inlet pump chamber (16) after being bent; one end of the outlet pipe (15) is connected to the outlet (3), and the other end is connected to the outlet pump chamber (17) after being bent.

5. The double-chamber series piezoelectric pump based on the Coanda effect jet element according to claim 4, characterized in that: The bending angle is 45°.

6. The dual-chamber series piezoelectric pump based on the Coanda effect fluidic element according to claim 4, characterized in that: The connecting pipe (13) is inclined at 45 degrees relative to the axis from the inlet (2) to the outlet (3).

7. The dual-chamber series piezoelectric pump based on the Coanda effect jet element according to claim 1, characterized in that: The bottom surface of the pump chamber is covered with a vibration diaphragm (5), and a piezoelectric vibrator (4) is arranged on the vibration diaphragm (5).

8. The dual-chamber series piezoelectric pump based on the Coanda effect fluidic element according to claim 1, characterized in that: The two pump chambers have the same structure.

9. The dual-chamber series piezoelectric pump based on the Coanda effect fluidic element according to claim 1, characterized in that: The bottom surface of the pump chamber is circular.

10. The dual-chamber series piezoelectric pump based on the Coanda effect fluidic element according to claim 1, characterized in that: Half of the pump chamber interface (18) is opened on the surface of a thicker section of the pump chamber, and the other half is connected to a thinner section of the pump chamber through a bell mouth structure.

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